1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device. More particularly, the present invention relates to a liquid crystal display (LCD) device and a method for manufacturing the same, capable of maintaining a cell gap and preventing press defects caused by application of a predetermined external pressure via the use of ball spacers.
2. Discussion of the Related Art
Hereinafter, a conventional liquid crystal display device will be illustrated with reference to the attached drawings.
FIG. 1 is a cross-sectional view illustrating a conventional liquid crystal display device.
As shown in FIG. 1, the conventional LCD device comprises a first substrate 10 and a second substrate 20 facing each other, gate lines 11 and data lines (now shown) arranged on the first substrate 10 such that they intersect each other, to define pixel regions, pixel electrodes formed in each of the pixel regions, and a liquid crystal layer (not shown) sealed between the first substrate 10 and the second substrate 20.
Here, a gate insulating film 14 is arranged over the entire surface of the first substrate 10 including the gate lines 11, the data lines (not shown) are arranged on the gate insulating film 14 such that the data lines cross the gate lines 11, a passivation film 15 is arranged on portions provided by the gate insulating film 14 including the data lines and pixel electrodes (not shown) are arranged in portions provided by the passivation film 15 corresponding to the pixel region.
A black matrix layer 21 is arranged on the second substrate 20 in portions corresponding to the gate lines, the data lines and the thin film transistors, color filter layers 22 are arranged on the second substrate 20 including the black matrix layer 21, and an overcoat layer 23 is arranged over the entire surface of the black matrix layer 21 and the color filter layers 22.
A first alignment film 16 is arranged over the passivation film 15 including the resulting structure on the first substrate 10 and a second alignment film 24 is arranged over the overcoat layer 23 on the second substrate 20.
In addition, a first column spacer 30 and a second column spacer 40 are arranged in different predetermined portions on the gate lines 11, wherein the first column spacer 30 has a first height corresponding to the gap between the first and second substrates 10 and 20 and the second column spacer 40 has a second height ΔH smaller than the first height.
The first column spacer 30 functions to maintain the cell gap between the first and second substrates 10 and 20, and the second column spacer 40, together with the first column spacer 30, resists an applied predetermined external pressure, thereby preventing deformation resulting from concentration of the pressure in any one of the spacers.
The aforementioned conventional liquid crystal display device has the following disadvantages:
First, when column spacers are employed, they have a large area in contact with the opposing substrate. For this reason, when a frictional force is applied by touch operations, the column spacers take a long time to return to their original state after the column spacers are pushed in one direction. Before returning an original state, display defects occur.
Second, when ball spacers are used instead of the column spacers in order to solve the disadvantages such as touch-defects, they tend to roll into pixel regions due to their mobility, causing other defects e.g. display defects.